Showing papers on "Encoder published in 1979"

On the structure of real-time source coders

Abstract: The outputs of a discrete time source with memory are to be encoded (“quantized” or “compressed”) into a sequence of discrete variables. From this latter sequence, a receiver must attempt to approximate some features of the source sequence. Operation is in real time, and the distortion measure does not tolerate delays. Such a situation has been investigated over infinite time spans by B. McMillan. In the present work, only finite time spans are considered. The main result is the following. If the source is kth-order Markov, one may, without loss, assume that the encoder forms each output using only the last k source symbols and the present state of the receiver's memory. An example is constructed, which shows that the Markov property is essential. The case of delay is also considered.

Combined Source-Channel Coding of Images

Abstract: A combined source-channel coding approach is described for the encoding, transmission and remote reconstruction of image data. The source encoder employs two-dimensional (2-D) differential pulse code modulation (DPCM). This is a relatively efficient encoding scheme in the absence of channel errors. In the presence of channel errors, however, the performance degrades rapidly. By providing error control protection to those encoded bits which contribute most significantly to image reconstruction, it is possible to minimize this degradation without sacrificing transmission bandwidth. The result is a relatively robust design which is reasonably insensitive to channel errors and yet provides performance approaching the rate-distortion bound. Analytical results are provided for assumed 2-D autoregressive image models while simulation results are described for real-world images.

Digital encoder-decoder

Abstract: A digital encoding and decoding system suited for use in a mobile trunked dispatch communication system capable of error correction, error detection, and detection of loss of synchronization. The encoder comprises a cyclic block encoder, an autosynchronization sequence combiner, a convolutional encoder, and a bit interleaver to encode information to be transmitted. The decoder comprises a bit de-interleaver, a convolutional decoder, an autosynchronization sequence combiner, and a cyclical block decoder to recover the transmitted information and also indicates whether any errors are present in the recovered information.

Low tire warning system

Abstract: An abnormal tire profile indicating system comprising a telemetry unit mounted on each wheel of a vehicle and a central receiver. Each telemetry unit comprises a piezoelectric transducer which is deflected with each wheel revolution when the tire profile is low. Deflecting the transducer produces an electric pulse. The transducer pulses are accumulated on a charge storage capacitor to provide a power supply. When the level of charge on the capacitor reaches a predetermined level, a counter commences counting the transducer pulses. When a predetermined number of pulses are counted, the counter renders a transistor conductive, which transistor connects the power supply capacitor to an encoder and a transmitter. The encoder produces encoded signals and resets the counter after a predetermined number of encoder signals are produced. The central receiver receives the modulated radio signals from each of the telemetry units. The counter limits the transmitter to transmitting only after a sufficient number of low profiles are detected to assure reliable operation and only after a sufficient number of wheel revolutions to meet FCC periodicity of transmission requirements. The reset counter limits the duration of transmissions to meet FCC requirements.

Some optimal partial-unit-memory codes

Abstract: A class of time-invariant binary convolutional codes is defined, called partial-unit-memory codes. These codes are optimal in the sense of having maximum free distance for given values of R, k (the number of encoder inputs), and mu (the number of encoder memory cells). Optimal codes are given for rates R = 1/4, 1/3, 1/2, and 2/3, with mu not greater than 4 and k not greater than mu + 3, whenever such a code is better than previously known codes. An infinite class of optimal partial-unit-memory codes is also constructed based on equidistant block codes.

Electronic theft prevention apparatus for vehicles

Abstract: Electronic theft prevention apparatus including a decoder integrally formed with a vehicle component and selectively enabling the operation thereof, an encoder accessible to a vehicle operator for providing coded instructions to the decoder to enable operation of the vehicle component, and data coupling apparatus for interconnecting the decoder and the encoder to permit data transfer therebetween.

A Case Study of Encoder Shift Scheduling under Uncertainty

Abstract: This paper illustrates a shift scheduling procedure for a commercial bank's encoder work force for check processing in the presence of daily work load uncertainty. The author presents a chance constraint model for determining the appropriate safety capacity, analogous to safety stock in inventory theory, to meet varying volume demands when forecast errors are present. A series of tests are conducted to evaluate the model's performance under different operating costs, forecast errors, and volume arrival rates, which are based on data collected at Chemical Bank. The results indicate this model provides low cost solutions. This study provides two contributions to managers and management scientists. First, even though the paper illustrates the encoder work force shift scheduling decision, the methodology presented can be extended to other service oriented organizations. The main elements that need to be present are: varying between day work loads, varying within day work loads, uncertainty in estimating work ...

Apparatus and method for replacement of a parallel, computer-to-peripheral wire link with a serial optical link

Abstract: There is disclosed herein an apparatus and method for communication between units in a data processing or communication system utilizing light conducting fiber instead of parallel electrical conductor cable. The serial optical link permits potentially higher speed transfers and longer link lengths and utilizes potentially simpler, cheaper and safer construction than is possible with a parallel electrically conductive cable link. Because of the inherent electrical characteristics of copper cables, parallel links are limited to transfer rates of approximately 5000 bytes per second and 100 feet maximum length. By taking advantage of the greater bandwidth of optical fibers and utilization of manchester or Bi-phase L coded serial data transfers and time division multiplexing, higher transfer speeds and longer link lengths may be achieved. Higher data transfer rates may also be achieved utilizing electrically conductive cables, however cables of larger and more expensive construction would be necessary to eliminate some of the inherent speed limiting properties in cheaper cables. With optical cables, the large bandwidth allows the use of relatively cheap components and a reduction in the number of lines needed between the CPU and the peripheral. Further, the larger bandwidths allow a potentially higher data transfer rate with some protocols despite the fact that serial format is used. In the preferred embodiment, a trigger generator senses when transfer of a data packet is desired. At that time, a header generator generates a header for the data packet, and a Manchester encoder latches the parallel data into a shift register with the first 3 bits used to generate the header. The header bits are shifted out of the shift register. A header generator modifies the clock signal to a Manchester encoder producing a non-Manchester data header. After the header is out, the data is encoded in Manchester format. A receiver at the opposite end of the optical link recovers the clock from the manchester encoded data, detects the header, and shifts the data into a shift register where it is transferred out in parallel format.

Encoder for length or angle measuring devices with high accuracy

Abstract: An encoder for measuring devices having a code plate including binary grating patterns arranged in a given regular fashion and forming a first scale, a linear sensor including photodiode elements arranged with fixed intervals and forming a second scale disposed in parallel with the code plate, and processor means for absolute-interpolating one pitch of the first or second scale on the basis of reading data or information obtained from the linear sensor corresponding to a relative position of the patterns to the elements. When the number of the scale divisions of the first scale within a fixed range is N, the number of the scale divisions of the second scale is N+1. Accordingly, when the first scale is a main scale, the second scale is a vernier scale. The processor means detects a phase inverting point corresponding to the interpolation point on the basis of the reading data. The processor means performs the absolute interpolation by detecting the phase inverting point.

Synchronizing technique for an error correcting digital transmission system

Abstract: The instant invention resides in a system, including an encoder and a decoder, for the transmission and retrieval of digital data over a transmission medium. The encoder includes an error correction encoding scheme which processes the data and produces an encoded bit stream including data and parity bits in either an interspersed or blocked relationship. A transmission bit stream is generated by modulo-2 adding the encoded bit stream with a predetermined sync sequence, which sync sequence is selected to provide optimum sync detection at the decoder site. The encoder modulo-2 subtracts said sync sequence from the received transmission stream, thereby producing a resultant which is monitored by an error correction detector. The detector produces an in- or out-of-synchronization indication as determined by the number of resultant bit stream detected errors.

Scrambled video communication system

Abstract: A television communication system wherein a composite video signal, is scrambled to prevent a stabilized picture from being displayed by a typical broadcast televison set receiving the scrambled video signal and encoded to enable verification, and wherein a received encoded scrambled video signal is verified and decoded to enable a stabilized picture to be displayed by a typical broadcast television set receiving the decoded video signal. The encoder includes a first circuit for offsetting the DC level of the reference color burst information in a composite video signal to a point nearly midway between the reference black and white levels of the video information; and for removing horizontal synchronizing pulses from the composite video signal to provide a scrambled video signal; a code word generator for generating a code word; and an insert circuit for inserting the code word in the scrambled video signal in regularly spaced positions that normally would be occupied by every nth one of the horizontal synchronizing pulses to thereby encode the scrambled video signal, wherein n is an integer greater than one. The decoder includes a video detector for receiving the encoded scrambled video signal; a code module for storing a predetermined code word; a verification device for comparing the predetermined code word with code words in the received encoded scrambled video signal and for providing verification signals when the predetermined code word is detected in the encoded scrambled video signal; and a second circuit responsive to the verification signals for restoring horizontal synchronizing pulses in the received video signal, and for restoring the DC level of the reference color burst information in the received video signal to the back porch level of the restored synchronizing pulses, to thereby provide the decoded video signal.

Analog to digital encoding system with an encoder structure incorporating instrumentation amplifier, sample and hold, offset correction and gain correction functions

Abstract: A new encoder for an analog to digital converter of the successive approximation type incorporates instrumentation amplifier and signal sample and hold functions within the encoder proper, thereby substantially simplifying the converter circuitry. An input analog current signal is applied to a sample and hold capacitor within the encoder through the encoder comparator at a time when the weighted reference signal to the comparator is set to zero. The capacitor stored analog voltage is subsequently applied to the encoder summing node and the encoding sequence ensues. The encoder may be provided with offset and gain correction circuitry, conventionally found exterior to the encoder. In one embodiment of the invention, offset correction is effected using the signal sample and hold capacitor.

Technique for reducing transmission error propagation in an adaptively predicted DPCM video encoder

Abstract: Propagation of transmission errors in adaptively predicted, DPCM encoded video signals is reduced by including a leak circuit (114) in the encoder (FIG. 1). The leak circuit modifies each prediction in response to local characteristics in the area of the picture being encoded.

An integrated per-channel PCM encoder based on interpolation

Abstract: Describes a novel technique called interpolation which has been used to integrate a per channel PCM encoder in a standard digital circuit technology. This encoder converts voiceband analog signals to both an oversampled 1-bit code and uniform PCM with /spl mu/-law companding noise. The circuit comprises approximately 550 integrated injection logic gates together with a resistive digital-to-analog converter, a voltage reference, and a simple differential amplifier. The encoder is part of a full PCM codec chip set suitable for a broad range of voiceband telecommunication applications.

Encoding device comprising predictors for thinned and unthinned patterns

Abstract: For selectively carrying out predictive encoding of an original pattern of a first tone on a background of a second tone and a thinned pattern having, in effect, the first tone on its background corresponding to the second tone, a device comprises a predictor responsive to a set of sample pulses representative of a few picture elements selected from those sampled from the original pattern and its background for producing each of prediction error pulses of a sequence, another predictor responsive to a set of pre-processed pulses representative of several picture elements selected from those sampled, in effect, from the thinned pattern and its background for producing each of error pulses of another sequence, a selector for selecting one of the original and the thinned patterns and consequently one of the predictors to produce a selection code indicative of the selected predictor, and an encoder for encoding the error pulses produced by the selected predictor into an encoded signal including the selection code. Preferably, each predictor is operable to produce for each error pulse a mode code indicative of one of two or more groups into which all allowable permutations of at least one of the two tones of the selected picture elements are classified and, in comsideration of which, codes are predetermined for all possible durations of same error pulse. The encoder uses the mode code for the respective error pulses in selecting some or all of the predetermined codes and arranges the selected codes in a predetermined order.

Modulo-PCM: A new source coding scheme

Abstract: A new source coding technique called MODULO-PCM (MPCM) is presented and it shown that this new scheme has essentially the same performance as linear predictive coding or transform coding. In contrast with the conventional schemes, MPCM employs a simple memoryless encoder and a moderately complex decoder incorporating the Viterbi algorithm. Bounds for distortion in MPCM systems fora first-order Gauss-Markov process are numerically calculated.

Method and apparatus for encoding/decoding a convolutional code to a periodic convolutional code block

Abstract: In a method and apparatus for convolutionally encoding a finite length digital data bit stream, the information samples arriving at the output of each encoder shift register are fed back to its input to simulate an infinite periodic data bit stream. Recirculation of the received information and parity symbols is also used for decoding.

Gray scale sync video processing system

Abstract: The blacker-than-black sync pulse of a standard video signal is replaced by a gray scale sync to increase picture signal, permit audio multiplexing and allow security phase inversion by means of encoder and decoder circuitry including a sync stripper, gate and timing generator, audio processor, phase code generator, color reference regenerator, blank and summing amplifier, and phase reversal amplifier.

Cylindrical encoder for use with fiber optics

Abstract: A fiber optic encoding device capable of long term reliable operation in hostile environments is disclosed. Various construction details which contribute to a compact device with high mechanical reliability are discussed. An encoder formed to a cylindrical geometry including a correspondingly shaped code plate is shown in detail. The code plate has a multiplicity of apertures arranged in rows to produce an encoded position signal of the type suitable for use in digital intelligence processing equipment.

Self-contained portable electrically sensed bathroom scale

Abstract: A portable bathroom scale is described wherein an optical encoder is used to determine the scale displacement in an unambiguous manner. A convenient circuit is used to transform the optical code on an encoder disc to the code needed to activate a decimal display. A mechanism is described for automatically activating the encoder and display when a person steps on the scale and deactivate the mechanism when the person steps off the scale.

Meter register encoder including electronics providing remote reading capability

Abstract: A self-contained meter register optical encoder including electronic signal generation, surge protection and power supply circuitry is remotely readable to supply timing and data signals to an external device when energized from an external power source.

Digital input apparatus

Abstract: Switch apparatus having a digital display is provided in accordance with the teachings of the present invention. The switch apparatus according to the present invention includes an encoder having a code pattern thereon which is scanned by a reader to produce multi-bit binary information to be displayed. A storage circuit having switch positional information stored therein is also provided and a collator is employed to compare the multi-bit binary information read by the reader with the positional information stored in the storage circuit. When a comparison is obtained a braking force is applied to inhibit scanning so that a switch position corresponding to stored positional information is obtained.

Facsimile transmission apparatus

Abstract: An input buffer (16) functions to store one line of data from a scanner (12) while feeding out a previous line to a run length encoder (17). The compressed data is fed from the run length encoder (17) to an output buffer memory (19) having a fixed capacity. The compressed data is fed to the output buffer (19) intermittently while it is fed out of the output buffer (19) continuously for modulation and transmission. In response to a start signal indicating that a line of data has been stored in the input buffer (16), fill bits are fed to the output buffer (19) at high speed until a full signal is generated indicating that the output buffer (19) is full. Then, a sync signal is fed to the output buffer (19) followed by compressed data from the run length encoder (17).

Data communication code

Abstract: An encoder of a transmitter converts digital data or analog signal information into an encoded sequence or waveform required by a communication channel. If a plurality of transmitters are to share a common channel or medium, then the correlation properties of the encoded signal are important. The encoding apparatus should employ a code which is not very susceptible to noise, yet will permit the detection of multiple transmissions of similar spectrum signals. The apparatus disclosed in this specification is concerned with a binary digital information encoder whose input is either a "zero" or "one" state. The encoder generates a ternary code sequence for encoding one binary input state with the sequence + 1,+1,0,0,-1,-1 and the other binary input state with the sequence represented by +1,0,+1,-1,0,-1.

Apparatus for encoding and decoding data signals

Abstract: An encoder/decoder is provided having two random bit generators which are cross-coupled in the Encoding mode with the data signal being directed to the input of each random bit generator. The data signal is also logically combined with the output of each random bit generator. In the Decoding mode the random bit generators are connected in a feedback configuration and the to-be-decoded signal is directed to the input of each random bit generator. The to-be-decoded signal is also logically combined with the output of each random bit generator to provide the decoded signal.

Keyboard encoder using priority encoders

Abstract: An electrical circuit is provided for converting the output from a keyboard into a binary form. At least two priority encoders are interfaced to the keyboard. Each priority encoder generates a binary code when a particular key is depressed. The individual binary outputs from the priority encoders are combined to provide a binary output which is representative of the particular key which has been depressed. In this manner, the output of the keyboard is encoded to binary form. The keyboard encoding system is disabled when a plurality of switches are simultaneously closed to thereby prevent errors caused by multiple switch closures.

Modular rotary shaft incremental encoder and a fixture and a method for pre-aligning an optical encoder stator

Abstract: A modular encoder with a dimensionally stable housing (35) which can be easily aligned for mounting on a motor housing. The encoder utilized a monolithic, in-line, sensor array (85) and a single light source (38) to achieve improved long-term performance and includes improved alignment means permitting a user to readily align the encoder with a motor. Pre-alignment (figure 8) of the mask (64) and sensor assembly simplifies the alignment performed by the user. The alignment means include mounting holes (70, 71) with diameters being greater than the diameter of the screws and cutaway portions in the housing.

Supervisory signaling for digital channel banks

Abstract: A digital transmission system is disclosed in which time slots in selected frames are reserved for supervisory signaling bits. These signaling bits can be used to represent a large number of supervisory states by assigning at least three bit patterns to each of two interleaved streams of supervisory bits. These bit patterns may include, for example, continuous ones, continuous zeros and alternating ones and zeros. A supervisory state encoder and decoder for these bit patterns are disclosed.

Transmission system using differential pulse code modulation

Abstract: This system comprises an encoder in which the differential PCM signal to be transmitted is formed as the difference between the incoming linear PCM signal and a prediction signal produced by a prediction filter comprising a local decoder receiving the said differential PCM signal. According to the invention the local decoder and the remote decoder are constructed in an identical manner by means of one or several filtering sections arranged in cascade, each filtering section being of the purely recursive or non-recursive type with one sole coefficient differing from zero and having been provided with its own roundoff (or truncation) device having a step size equal to the quantizing step of the differential PCM signal, the incoming linear PCM signal being rounded (or truncated) in the same manner. This construction enables the cascade arrangement of encoders and decoders without any further degradation of the signal then the degradation produced by the first coding.

Automatic dialing device

Abstract: PURPOSE:To ensure an effective operation of the automatic dialing device, by detecting the remote signal sent from the calling side and then securing the decision of the address and the priority of the address by the output signal. CONSTITUTION:Trunk circuit part 3 detects the incoming, catches main wire 1 and then detects the remote signal. This remote signal is then sent to remote signal detecting part 5 to be identified at remote signal identifying part 5a. Thus the identification signal is sent to encoder 5b. Then address selecting part 6 decides the address as well as the priority of the address by the output signal sent from encoder 5b. In other words, part 6 incorporates data selectors 6a, 6b and 6c plus control part 7, and thus the writing is carried out to selectors 6a-6c through output terminals 7a-7c and by the function of part 7. As a result, the address and its priority can be changed even at a remote place by using the telephone circuit, thus ensuring an effective operation of the automatic dialing device.